Tail fuze for an ordnance missile



SePt- 10, 1957 R. H. BLAIR ETAL 2,895,623

TAIL FUZE FOR AN ORDNANCE MISSILE 5 Sheets-Sheet2 FL/led Sept. 7, 1951 @www E mm NQ mo. Nm

INVENTOR. R. H. BLAH J. L PERTSCH BY HRSCRIBNER 40g/M QPM m/M Arm/s.

Sept. 10, 1957 R. H. BLAIR ET AL TAIL FUzE FOR AN oRDNANcf: MIssILE Filed Sept. 7, 1951 3 Sheets-Sheet 3 ilnited States Patent 2,8%,523 Patented Sept. li), i957 thee seams TAIL FUZE non AN onnNaNci: Mrssnln Application September 7, 195i, Serial No. 245,566 7 Claims. (Cl. 14m-81.2)

This invention relates to a fuze and more particularly to an impact inertial actuated tail fuze for use in a guided missile, drop bomb or the like.

The present invention provides a new and improved tail fuze in which dual explosive trains and tiring means are employed and which permits independent operation of one train with respect to the other and thus assuring explosion of the bomb upon impact thereof with the target should, for any reason, one of the dual explosive trains fail to function as the ring means is forcibly moved into engagement therewith upon impact of the bomb with the target. Furthermore, by the aforesaid arrangement a new and improved tail fuze is provided having dual liring means constructed and arranged to be actuated and tired independently upon impact of the missile with the target thereby obviating the need of both a nose and tail fuze as heretofore employed in prior art devices, such prior art missiles depending on the operation of either the nose or tail fuze to cause detonation of the main charge and explosion of the missile thereby to reduce the probabilities of duds due to fuze failure.

The purpose of the present invention is to provide a tail fuze having new and improved dual tiring means whereupon it is possible to dispense with the usual nose fuze now employed with some ordnance missiles and thus not only to maintain a high degree of impact performance without the use of the customary nose fuze but also to provide a considerable saving to the Government. Furthermore, the present invention provides a new and improved tail fuze structure for use with an ordnance missile which is constructed in such a manner as to insure detonation of the main charge disposed within the missile upon impact of the missile with the target and which has a high average impact performance, maximum sensitivity, admirable safety features and simplicity thereby permitting mass production of the fuze rapidly and economically.

One of the objects of the invention is the provision of a tail fuze for `an ordnance missile in which new and improved means are employed for maintaining the fuze in an initial safe condition until the missile has been released from an aircraft in flight and travelled a predetermined distance therefrom.

Another object is to provide a new and improved tail fuze in which dual firing means are employed and adapted to be functioned independently upon impact of the missile with the target thereby to explode the missile in time delayed relation with respect to the impact.

Another object is to provide a new and improved fuze in which a normally locked inertial mass is employed and adapted to be released during the travel of the missile toward a target and to tire a pair of explosive trains independently upon impact of the missile with the target.

A further object is to provide a tail fuze for use with an ordnance missile and having new and improved means for maintaining the fuze in a safe condition until the missile has been released from an aircraft in ight and in which new and improved means are employed for arming the fuze when the missile is released and has travelled 2 a predetermined distance from the aircraft after being released therefrom.

A. still further object is to provide a new and improved tail fuze in which means are provided for rendering the fuze moistureproof and in which means are provided for initiating a pair of detonators independently as an inertial mass is forcibly driven forwardly in response to impact of the missile with a target thereby to explode the missile in time delayed relation with respect to impact of the missile with the target.

Still another object is to provide a new and improved fuze for an ordnance missile which is economical to manufacture, reliable in operation, highly sensitive upon target impact, and possesses the qualities of durability and detonator safety during handling and transportation.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following deatiled description when considered in connection with the accompanying drawings wherein:

Fig. l is a fragmentary view of a guided missile partially in elevation and partially in section and employing the tail fuze of the present invention;

Fig. 2 is an enlarged central longitudinal section of the fuze in an unarmed position;

Fig. 3 is a view similar to Fig. 2 with the fuze in an armed position;

Fig. 4 is a transverse sectional View taken on line 4 4 of Fig. 2;

Fig. 5 is a transverse sectional view taken on line 5 5 of Fig. 2;

Fig. 6 is a detail sectional view taken on line 6-6 of Fig. 2;

Fig. 7 is a transverse sectional view taken on line 7-7 of Fig. 3; and

Fig. 8 is a detail View of one of the inertial operated masses and striker arrangement.

Referring to the drawings and more particularly to Fig. 1 thereof, there is shown thereon a fragmentary portion of a guided missile or bomb generally indicated by the reference character 10 `and comprising a casing 11 having the tail fuze 12 of the present invention secured thereto preferably by threaded engagement. therewith, the casing 11 being enclosed in a shroud 13 and having an explosive charge i4 arranged therein and adapted to explode the' missile in time delayed relation with respect to impact of the bomb with a target.

Disposed within the open end of the shroud and secured therein in any suitable manner is the usual generator 15 having a driven shaft 16 adapted to be driven by a propeller 17 secured thereto and rotated in response to the air pressure thereagainst as the missile is transported through the air by the carrier plane, the missile being detachably secured to the carrier plane and adapted to be released therefrom and guided toward the target in the usual manner.

It will be understood, however, that during `the air travel of the plane and in response to the aforesaid rotation of the propeller 17 suicient electrical energy is produced by the generator to operate the arming motor 18 when the missile is released from the aircraft, the motor being electrically connected to the generator and disposed within the shroud and secured thereto by a support structure 19. The electrical circuit between the generator and motor is interrupted by a normally open switch 21 comprising `a pair of electrical contacts 20 and a spring pressed plunger 23, disposed within `the shroud and maintained opened by the usual arming wire 2.2 passing through an aperture within the plunger until the missile is released from the aircraft whereupon .the arming wire is withdrawn and releases the plunger for movement to a switch closed position. When this occurs, an electrical :a transversely disposed pin 28, the free ends thereof being respectively and slidably arranged within a pair of elongated diametrically' disposed slotsV 29 formed -in the sleeve 25. By the aforesaid arrangement, it willY be -understood that a driving Vand Vsliding connection is provided Y between the arming andthe motor `shaft and thus permitting movement of the arming shaft outwardly to an armed position in response to rotation thereof by .the motor.

The fuzel12 comprises a casing generally indicated by the reference character 31 and secured to the explosive casing 11 as by threaded engagement therewith,` one end portion of the fuze easing extending into the casing 111 and embedded in ,the explosive charge 14, Figs. 2

and 3.

Secured to one end ofthe casing 31 as by threaded engagement therewith .as at 32 is a cap or member 33 comprising-` afbody portion 34 having an elongated nipple 35 Y formed thereon and extending outwardly therefrom. As

shown .more clearly on Figs.' 2 and 3, an O ring 36 is disposed between the cap 33 and fuze casing for providing a watertight'connection therebetween.

Threaded -on :the nipple 35 as at 37 and secured .thereto by'a pinf38 is a sleeve 39, the sleeve being providedv with .an opening 41 adapted to be inalignment with a correspondingopening 42 arranged in the arming shaft 27 for receiving the usual safety pin thereby .to prevent rotation 'of the arming shaft during handling and transportation of the missile. It will be understood, however, that as the missile is. attached to the carrier the safety pin is withdrawn from the aforesaid -openings 41 and 42 `and the arming wire 22is inserted therein and `thus arming of the fune will not occur until the missile is released from the carrier plane in ilight and the arming wire is withdraw-n from the aforesaid openings as the missile Vfalls away"therefrom.

As more clearly shown in Figs. 2 and 3, a watertight connection is provided between the shaft 27, nipple 35 and sleeve 39 by means of a washer 44 and O ring 45, the washer being arranged in abutting engagement with a shoulder 46 formed within the nipple 35 and constituting an enlargement of the centrally disposed bore 47 formed in the nipple. The O ring is compressed between the washer 44 and end wall 48 of the sleeve 39 and into sealing engagement with the shaft 27 and the wall dening the bore 47 as thesleeve is threaded on the nipple. A containerl or cup-shaped member 49 is secured to the other end of the fuze casing in any .suitable ymanner preferably by threaded engagement therewith and indicated by the numeral 51, a watertight seal being'formed between the container and fuze casing by employing an O ring 52. Y

' A rotor support generally indicated by the reference characterSS is arranged within the container 49 and comprises a body portion 54 having a transversely disposed bore'55 extending therethrough in which is rotatably supported Van arming rotor 56, the support being secured to the fuze casing 31fas by screws 50, Fig. 7, and one end of the support 53 is provided with a well 57 having a booster` charge 58 arranged therein and supported by container 49 and disposedbetween a pair of anti-friction discs 59 composed of any material'suitable for the pur pose suchjfor example,as bond paper or the like, for protecting the booster charge as the container is screwed into place on .the casing the other end of the support having formed thereinra relatively shallow recess 61 in which is arranged the reduced end portion v62 of the fuze casing 31, Figs. 2 and 3, the support beingV maintained in position by recess 61 and in clamping engagement with the fuze by the aforesaid (screws 50) land thus movement 4of the support is prevented. The support 53 is provided with a pair of spaced bores 63 in communication with the well 57 and the transverse bore 55 and has a Vpair of lead-in charges 64 disposed therein respectively.V

when the rotor is released and moved to an armed position. Endwise movement of the rotor in therwrong direction ywithin'the bore 55 upon Vassembly is prevented by a flange 72 formed on one terminal portion 66 and arranged in a counterbore 73 and in abutting engagement with Ia shoulder 74 thereinj and .endwise movement in either direction after assembly is prevented Vby a pin 75V secured to the support and disposed within a slot 76 formed in the rotor and in abutting engagement with 'the walls defining the slot. y

The rotor is moved .to an armed position when released by a pair of coil springs 77 disposed about .the terminal portions 66 of the rotor respectively, itbeing understood, however, that whenV the rotor is moved to an armed position further movement is prevented by the pin 75. Each spring 7'7 comprises a pair of arms orV members 78 and 79, each arm 78 is arranged in a slot 81 formed in support'53, and each arm 79 being disposed Vin a slot 82 formed in the end portions 66 of the rotor. Asmost clearly shown on Figs. 6 and 7, the terminal :portions of eachfmember 79 are bent at a right angle as at 80, into engagement with flat surfaces 83 formed on each member 66. By theraforesaidrarrangement, it will be obvious that the springs 77 are normally under tension when the arming rotor is in an unarmed position, Figs. 2 and 5, and upon release of the arming rotor by the arming shaft 27 as the arming shaft isl moved out of the bore 84 formed in the rotor and in response to'rot-ation'of the -arming shaft thespring will rotate the rotor to an armed position, Figs. 3 and 6. Springs 77 may be of different size to facilitate proper assembly'of the rotor.

The arming shaft 27 comprises two Vsections designated bythe reference characters 85 and 86, the section 85 being of larger diameter than the section 86 and having a threaded portion thereon in threaded engagementwith the body 34 of cap 33 as at 87 whereby the shaft is moved outwardly in response to rotation of the mot-or suciently to move the section 86 out ofthe bore 84 whereupon the Arotor is moved from a safe position to anarmed position by the aforesaid springs. The section 85 is provided with a conical frusto portion 88V and is secured and locked to the section 86 in any suitable man-v striker 98, each member 97 being secured withinV the bores 96 by a pin 99. Y

As shown more clearly on Fig. 2, each member 94 is normally locked to the fuze casing by a detent 191mmprising a body 102Y slidably'arranged within a bore' formed in the members and having one endY thereof dsposed within aY-recess 104`formed inthe fuze casing 31,

the other end of each body 102 being reduced in diameter and extending through an opening 105 arranged in a retaining washer 106 secured within each bore 103 and into engagement with the shaft section 85. By .the aforesaid arrangement, the members 94 are maintained locked to the fuze casing by -the aforesaid detents until the arming shaft is moved outwardly suiiiciently to permit the detents 101 to be urged out of engagement with the recess 104 by springs 107 disposed within each bore 103, one end of the springs being in engagement with a flange 108 formed on each detent 101, the other end thereof being 1n engagement with a wall 109 defining the bottom of the aforesaid bores 103.

As most clearly shown on Figs. 2 and 3, the fuze casing 31 has formed therein .a pair of diametrically disposed bores 111, each bore having a cartridge 112 secured therein. Each cartridge comprises a primer 113, percussion pin 114 in engagement therewith, delay element 115, detonator 116, and a iash chamber 117 formed in each cartridge and disposed between the primer and delay element. It will be understood, however, when the .fuze is in an armed position, Fig. 3, the detonators 69 1n the arming rotor 56 are in alignment with detonators 116 in the cartridges and also in alignment with lead-in charges 64 and thus a complete explosive train is provided from primers 113 to the booster charge 58.

As shown on Fig. 7, the arming rotor 56 is locked in an armed position by a detent 118 arranged within a bore 119 formed in the rotor support 53 and urged into a recess 121 formed in the rotor by a spring 122, one end of the spring being in engagement with the detent 118 and the other end thereof being in engagement with a disc 123 disposed within bore 119 and secured therein in any suitable manner.

A pair of diametrically disposed pins 125 is secured to the fuze casing 31, Fig. 4, and extends into recesses or notches 126 respectively arranged within the inertial members 94 thereby to prevent rotation of the members within chamber 93 and with respect to each other and thus maintaining the strikers 98 in alignment with the percussion pins 114. Each member 94 is provided with an anti-creep and shock absorbing spring 127 disposed about the device 97 thereof respectively, one end of each spring being in engagement with the bottom wall of each bore 9S, the other end of each spring being disposed within a bore 128 formed in the fuze casing and in engagement with the bottom wall thereof respectively. The operiation of the device will be best understood by consideration of a specific example.

Let it be assumed, for the purpose of description, that the missile is released from an aircraft in flight and guided toward a target. As the missile falls away from the aircraft the arming wire 22 is withdrawn from openings 41 and 42 formed in sleeve 39 and arming shaft 27 respectively and concurrently therewith the arming wire is withdrawn from the switch 21 a-nd the switch is moved to a closed position whereupon an electrical circuit is completed from the generator 15 to the arming motor 18 and thus the motor is set in operation, it being understood, however, that during the travel of the plane and in response to rotation of the propeller 17 electrical energy is produced by the generator. When the arming shaft 27 of the fuze has been rotated a predetermined number of revolutions in response to rotation thereof by the motor shaft 24, the fuze is armed, Figs. 3 and 7.

`During the arming of the fuze, the arming shaft 27 will make a suiiicient number of revolutions within the cap 33 to be moved outwardly to an armed position due to the threaded connection between shaft `and cap, Fig. 3. When this occurs, the portion 86 of the arming shaft is withdrawn from the arming rotor 56 and the arming rotor is urged to an armed position by the springs 77 and locked therein by detent 11S. Furthermore, when the arming shaft has been moved to an armed position the normally locked inertia operated devices 94 are released for sliding movement as the detents 101 carried thereby are urged out of engagement with the aforesaid recesses 104 by springs 107 and thus upon impact of the missile with a target the devices 94 are moved inwardly in response thereto whereupon the strikers 98 thereon are driven into engagement with percussion pins 114 and thus the pins 114 fire the primers 113 as they are driven into firing engagement therewith by the aforesaid strikers. The Hash within the flash chamber 117 caused by the primers as the primers are red ignites the delay elements 115 which ire the detonators 116. The detonators 116 re the detonators 69 in the arming rotor S6 which fires the lead-in charges 64 which, in turn, re the booster charge 58 and main charge 14, thus exploding the missile.

if desired, the fuze may be provided with a discriminating feature particularly adapted for use in missiles against naval targets whereby the device will function when ia short period of time has elapsed after impact with a ship or the like and also when a longer period of time has elapsed after impact of the missile with the surface of a body of water. The aforesaid time delay operation of the fuze may be accomplished such, for example, as by changing the sensitivity of inertia masses, by changing the weight of the inertia masses, by increasing the tensile strength of the springs supporting the inertia masses, by providing shear elements therefor, or by a combination of the aforesaid methods. However, it will be understood, that by employing one of the above mentioned methods the sensitivity of reaction of the inertia weights is so adjusted that it will not actuate upon water impact but on the other hand it will actuate upon target impact such, for example, as the deck of a ship or the like. Furthermore, it will be understood that short fuze delay elements will be installed beneath and in alignment with the aforesaid modified arrangement of the inertia masses.

Briefly stated in summary, the present invention contemplates the provision of a new .and improved fuze for ordnance missiles in which independently actuated dual inertial devices are employed for tiring dual explosive trains therein in time delayed relation with respect to impact of the missile at the target and in which a discriminating feature is employed whereby the fuze will not function upon water impact but will function upon target impact. Obviously many modications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practised otherwise than as specifically described herein.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

l. A tail fuze for a guided missile adapted to be released toward a target from an aircraft in flight and red by impact with a target and comprising a casing supported by the missile, a releasable arming rotor supported within the casing in an initial safe position and adapted to be rotated to an armed position when released, means including an arming shaft rotatably supported in said casing for releasably locking said arming rotor in said initial safe position and for releasing the arming rotor when the arming shaft has been rotated a predetermined amount, normally ineffective electrical means on said shaft for rotating the shaft said predetermined amount upon being rendered eifective, electrical switching means for rendering said electrical means eifective when said missile has been released from an aircraft, a pair of resilient devices on said arming rotor for rotating the rotor from the initial safe position to an armed position as the arming rotor is released, a pair of percussion devices arranged within said casing, a pair of inertial actuated firing devices for firing said percussion devices as the tiring devices are driven into iiring engagement therewith 'in response to said impact, and locking means releasably engageable by said arming shaft for retaining said inertial actuated ring devices initially locked to said casing until the arming shaft hasrotated,saidpredetermined amount. Y l

A.2,Artazil fuze forragiguided missile adapted tofbe;re leasedetoward a .target from .anaircra-ftin flight and'to Vbe firedeby impact with a target and comprising a casingrsupported by the missile, a booster charge arranged Within said casing, a releasable arming, member rotatably supported Within the casing in an initial safe position, means including, an Larming shaft rotatablysupportedin said c asing for jreleasablylocking said arming member in said initial safe position and for releasing the arming member whenthe arming shaft has been rotated a predetermined amount initially inoperative `electricahmotor,means on said; shaft for rotating said shaft said` predetermined amount upon being rendered -operati'vejelectrical switching, means'for renderingsaid electrical4 motor means effectiveiwhenY said missile has been released from an aircraft, a pair-of resilientV devices lonsaid arming vmember for rotating the vmemberv from theinitial-safeposition to an armedy positionasthe arming memberis released, aV pair of fpercussionrdevices. arranged Within ,saidcasing, a pair of inertial actuated firing devicesn for firing saidpercus-` sion devices as the firing devices Arare driven into firing engagementtherewith in response to said impact, and means includinga pair of detonators arranged within said armng'member in firing relation with respect to said percussion devices for firing said booster charge in time delayed -rel'ation with. respect to said impact.

l.V A tail fuze for a guided missile adapted to be released toward atarget from an aircraft in flight and to befiredby'impact with atarget, a casing supported by the missile, a releasable arming member rotatably supported Within said casing in an initial safe position, means includingan arming shaft rotatably supported in said casing for releasably locking said arming member in said initialisafe position and for releasing the arming member when the armingshaft has been rotated and moved a predetermined amount, normally ineffective electrical circuit means including an electrical motor operatively connected to said shaft V`for rotating the shaft said predetermined amount, said circuit means further including an electrical switchfor rendering said circuit means effective when said missilehasbeeny released from an aircraft, a pair of spring members secured to the casing and arming member respectively for rotating the arming member from the initialsafe position to an armed position as the arming member is released, a pair of percussion devices arranged within said casing, a pair of inertial actuated masses releasably locked to said casing, means for locking said masses to the casing and adapted to release said masses for sliding movement therein when the arming shaft has been moved said predetermined amount, a pair of firing devices secured'to said masses respectively in alignment with said percussion devices and actuated into firing engagement with said percussion devices when said masses have been released and movedV a predetermined amount in response to said impact, a booster charge in said casing, and means including a pair of detonators arranged within said arming member and brought into alignment with said percussion devices as' the arming member is rotated to said armed position for firing said booster char-ge in time delayed relation with respect to said impact.

4. A tail fuze for a bomb adaptedto be released from an aircraft in ight toward a target and comprising a casing supported by-said bomb,.an explosive charge arranged in said casing, initially ineffective electrical means including an electrical generator and motor operatively connected 'thereto for arming the fuze upon being rendered effective, a spring actuated electrical switch for rendering said electrical meanseffective when said bombhas been released from an aircraft and during the freefli'ght of the bomb toward said target, and means including a pair of1percussi`on devices arranged Within said casing for firing. said explosive charge when therfuze armed, said tiringf'means including'a pair of inertial actuated firing' devices initially vlocked .to the casing by said'arminglmeansrfor firing said jpercussion'devicesin response to'k the force applied; thereto 'as the; bomb Y,strikes said-target. Y i 'Y A 5. A trail fuze for Van explosive; missile adapted .to be releasedtoward a target from an aircraft in flight and fired by impact-.with-aitarget, a casingI supported by said missile, afreleas'able arming member rotatably supported within-said. casing in `an initial safe positionand havingV a pair of detalla-tors therein,v means including anarming shaft rotatably supported .inrsaid4 casing for `releasably Vlocking said arming member in said` initial safe position ing Wire detachably secured thereto for closing said circuit as the V4arming wire is detached therefrom and the switch'is actuated to a closed position, a-'pair of springs securedto the casing and arming member respectively for rotating the arming member from the initial safe positionV to an armed position as the arming member is released, a. pair of inertial actuated elements releasably locked to-said casing, a pair of spring urged detentsV arranged withinsaid elements and normally in engagement with `said arming shaft and respectively disposed Within a pair of recesses formed in the casing for locking said elements to the casing and adapted to release the masses for sliding movement therein when the detents are moved outl ofengagement With said recesses, cam means on saidV arming shaft for permitting said movement of the detents When the arming shaft has been moved said predetermined amount, a pair of percussion devices arranged Within said casing, a pair of firing devices secured to said inertial elements respectively inralignment with said percussion devices and driven into firing engagement with said percussion devices in response to saidV impact, a pair of time delayY elements arranged within said casing in alignment withv said detonators and said percussion devices for firing said detonators, and explosive means fired by said detonators for exploding said missile.

6. In a tail fuze for an explosive ordnanceV missile adapted to be released from an aircraft in flight toward a target, the combination of la fuze secured to the tail end of the missile, means includinga normally locked arming shaft rotatably supported Within said fuze for arming the fuze when the shaft has been released and rotated a predetermined number of revolutions, an arming Wire adapted to be secured to an aircraft and releasably connected to said arming shaft for releasing the shaft for rota-tive movement as the missile is released from an aircraft,means including an electrical motor operatively connected to said arming shaft for rotating the shaft said predetermined number of revolutions as the motor Vis set in operation, means including an electrical Vgenerator for settingfthe motor in operation, a normally openrspring actuated electrical switch having'said arming wire detachably secured thereto for electrically interconnecting Vsaid electricalmotor and said electrical generator upon actuation ofsaid switch to a closed position by detachment of the arming wire therefrom as the missile is released from an aircraft, a pair of percussion devices arranged in said fuze, a pairvof inertial actuated elements sli-dably arranged` within said casing and movable in response to the impact of the missile vwith'said target, a pair of firing devices secured to saidelements respectively and actuated into firing engagement with said percussion devices when the elements have been fmoved apredetermined amount, and

means including a pair of time delay elements fired by Cil safe position, means including an arming shaft rotatably supported within said casing for.releasably locking said arming member in said initial safe position and for releasing the arming member when the arming shaft has been rotated and moved axially a predetermined amount, an arming Wire adapted to be secured to an aircraft and releasably connected to said arming shaft for releasing the shaft for rotative movement as the missile is released from an aircraft, means for rotating said arming member from said initial safe position to said armed position as the arming member is released, a normally open electrical circuit, a normally open spring actuated switch included in said circuit and having said arming wire detachably secured thereto for closing said circuit as the arming wire is detached therefrom and the switch is actuated to a closed position, an electrical motor included in said circuit and operatively connected to said arming shaft for rotating said shaft as the motor is set in operation, a gen erator included in said circuit for supplying suicient electrical energy to the motor to cause the motor to be set in operation, means operatively connected to said generator and actuated in response to the air pressure thereagainst for generating said electrical energy therein during said flight, a pair of percussion devices arranged within the casing, a pair of inertial actuated masses releasably locked to said casing, means for releasably locking said masses to the casing and adapted to release said masses for sliding movement when the arming shaft has been moved said predetermined amount, a pair of firing devices secured to said masses respectively in alignment with said percussion devices and actuated into tiring engagement therewith when said masses have been moved a predetermined amount in response to said impact, a booster charge arranged within said casing, and means including a pair of detonators arranged within the arming member `and brought into alignment with said percussion devices as the arming member is rotated to said armed position for firing said booster charge in time delayed. relation with respect to said impact thereby to explode said missile` References Cited in the tile of this patent UNITED STATES PATENTS 1,690,331 Brayton Nov. 6, 1928 1,916,244 Woodberry July 4, 1933 2,409,205 Graumann Oct. 15, 1946 2,511,872 Parker .lune 20, 1950 FOREIGN PATENTS 257,335 Great Britain Aug. 27, 1926 866,962 France June 23, 1941 

